Izotope Leveler


I have an old cassette speech recording which I am trying to clean up and Izotope Rx9 standard is doing a great job.
However, the technology used was poor, and the recordist was moving around, or the tape was poor, causing quite a lot of level loss, almost dropout, in places.
I'd love to try the Izotope leveler but this only comes with the Advanced version of Rx, several hundred dollars for a single plugin....
Is there a standalone plugin that will detect and correct sudden drops in level?